<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>点击轮播图</title>
</head>
<style>
        .container {
            position: relative;
            width: 600px;
            height: 400px;
            margin:100px auto 0 auto;
            box-shadow: 0 0 5px green;
            overflow: hidden;
        } 
        .wrap {
            position: absolute;
            width: 4200px;
            height: 400px;
            z-index: 1;
        }
        .container .wrap img {
            float: left;
            width: 600px;
            height: 400px;
        }
         .container .buttons {
            position: absolute;
            right: 40%;
            bottom:20px;          
            z-index: 2;
        }   
        .container .buttons span {
            margin-left: 10px;
            display: inline-block;
            width: 7px;
            height: 7px;          
            background-color: #D4D4D4;
            text-align: center;
            color:white;
            cursor: pointer;           
        }
        .container .buttons span.on{
            background-color: #558949;
        }
        .container .arrow {
            position: absolute;
            top: 35%;
            color: green;
            padding:0px 14px;
            border-radius: 50%;
            font-size: 50px;
            z-index: 2;
            display: none;
        }
</style>
<body>
    <div class="container">
        <div class="wrap" style="left:-600px;">
            <img alt="">
            <img src="https://i.postimg.cc/qRRLS16Q/susu0.jpg" alt="">
            <img src="https://i.postimg.cc/mgsKJGLw/susu1.jpg" alt="">
            <img src="https://i.postimg.cc/mgsKJGLw/susu1.jpg" alt="">
            <img src="https://i.postimg.cc/mgsKJGLw/susu1.jpg" alt="">
            <img src="https://i.postimg.cc/qRRLS16Q/susu0.jpg" alt="">       
        </div>
        <div class="buttons">
            <span></span>
            <span></span>
            <span></span>
            <span></span>
            <span></span>
        </div>   
    </div>
    
    <script>
    	var wrap = document.querySelector(".wrap");         
        var index = 0;
        var dots = document.getElementsByTagName("span");
        function showCurrentDot () {
            for(var i = 0, len = dots.length; i < len; i++){
                dots[i].className = "";
            }
            dots[index].className = "on";
        }
        index++;
            if(index > 4){
                index = 0;
            }
        index--;
        if(index < 0){
            index = 4;
        }
        showCurrentDot();
         for (var i = 0, len = dots.length; i < len; i++){
            (function(i){
                dots[i].onclick = function () {
                    var dis = index - i;
                    if(index == 4 && parseInt(wrap.style.left)!==-3000){
                        dis = dis - 5;     
                    }
                    //和使用prev和next相同，在最开始的照片5和最终的照片1在使用时会出现问题，导致符号和位数的出错，做相应地处理即可
                    if(index == 0 && parseInt(wrap.style.left)!== -600){
                        dis = 5 + dis;
                    }
                    wrap.style.left = (parseInt(wrap.style.left) +  dis * 600)+"px";
                    index = i;
                    showCurrentDot();
                }
            })(i);            
        }
    </script>
</body>
</html>
